What are T-Bills? They seems to be like Bonds but with short lifespan. I ask this because I’ve read that people in US suggest to have them instead of plain cash. It should be as safe as cash but with a bit of interest added to it. Do they exist here?

Treasury bills (or T-bills) mature in one year or less. Like zero-coupon bonds, they do not pay interest prior to maturity; instead they are sold at a discount of the par value to create a positive yield to maturity.

So I imagine you can buy it for example for $97 and in one year you will get $100 back.

I did that and got the same answer. Still no idea if they exists here in CHF.

Swiss yield curve is below 0% all the way up to 10 year maturities, so why the heck would you want to buy any?

Spend 0.86% right now, spread the rest among under 100k deposits in swiss banks at 0% and you’ll end up practically with the same result in a year as if you bought a “swiss 1 year t-bill” if they emitted it.